Assign Bandwidth Across Several
A consists of a central office node, called an optical line terminal, one or more user nodes, called optical network units or optical network terminals, and the fibers and splitters between them, called the optical distribution network. is an term, whereas is an Optical Filter. in multiple tenant units, the may be bridged to a customer premise device within the individual dwelling unit using technologies such as ethernet over twisted pair high speed standard that can operate over any existing home wiring power lines, phone lines and coaxial cables. an is a device that terminates the and presents customer service interfaces to the user. some implement a separate subscriber unit to provide services such as telephony, ethernet data, or video. the provides the interface between the and the service providers network services. these typically includeinternet protocol ip traffic over ethernetstandard time division multiplexed tdm interfaces such as sonet or sdhatm uni at terminates the and presents the native service interfaces to the user. each only reads the content of those packets that are addressed to IR Filter. encryption is used to prevent eavesdropping on downstream traffic. upstream bandwidth allocationthe is responsible for allocating upstream bandwidth. because the optical distribution network is shared, upstream transmissions could collide if they were transmitted at random times. can lie at varying distances from the, meaning that the transmission delay from each is unique. the measures delay and sets a register in each via ploam physical layer operations and maintenance messages to equalize its delay with respect to all of the other on the once the delay of all has been UV Filter, the transmits so called grants to the individual. a grant is permission to use a defined interval of time for upstream transmission. the grant map is dynamically re calculated every few milliseconds. the map allocates bandwidth to all, such that each receives timely bandwidth for its service needs. some services pots, for example require essentially constant upstream bandwidth.